Fix demo playback when using the Rift
Fix color blending mangling the HUD
Don't roll the camera at player death when using an Oculus Rift
Prevent HUD from rolling when oculus sensors are reset
Allow setting IPD manually + fixes

-r_oculusrift_ipd now can be used set an ipd between 0 and 100mm
-If r_oculusrift_ipd is set outside of that range (e.g., -1) it will
revert to the value provided by LibOVR
-r_oculusrift_prediction now reports the value set
-Magnetic drift correction now reenables after a orientation reset
-Magnetic drift correction now creates and deletes necessary resources
when enabled/disabled
-Eliminated extra math in R_InitHMDRenderer()

Conflicts:
	Quake/gl_rmain.c
	Quake/gl_rmisc.c
	Quake/oculus_sdk.cpp
	Quake/oculus_sdk.h
	Quake/r_renderhmd.c
	Quake/r_renderhmd.h
Implement partially decoupled aiming mode

-Implemented as r_oculusrift_aimmode 5
-Similar to vr_moveaim_mode 3 for TF2
-Mouse can free aim within a deadzone. Moving to the edges will turn the
view.
-Viewing is decoupled, but will move the point of aim when it reaches
the edge of the dead zone (for yaw).
-r_oculusrift_aim_deadzone can adjust the angular area of the deadzone,
and is limited to range 0-70 inclusive. Setting values outside this
range sets it to the closest edge of the range.
Cleanup

Switched a few places to using CLAMP() macro.
Updated r_oculusrift_crosshair

-Crosshair is scales so it is the equivalent of 3 pixels wide for point,
2 pixels wide for line
-Point is now a rounded dot
-Added mode 3, which is a point projected (roughly) to infinity
Merge pull request #5 from dghost/master

Bunch of changes + bug fixes